Generally, a three dimensional (3D) image (or a stereoscopic image) provides user's eyes with a stereoscopic effect using the stereoscopic visual principle. A human being senses depth through a binocular parallax caused by a distance between their eyes spaced apart from each other by about 65 mm, such that the 3D image enables both right and left eyes to respectively view their associated planar images, and a human brain merges two different images with each other, resulting in a sense of depth and a sense of presence in the 3D image.
For example, the above-mentioned 3D image display method may be classified into a stereoscopic scheme, a volumetric scheme, a holographic scheme, etc. In addition, a 3D image display device adds depth information to two dimensional (2D) images or uses left view image information and right view image information, such that a user of the 3D image display device can feel a sense of vividness and a sense of reality in a 3D image.
In addition, a method for allowing the user to view the 3D image may be exemplarily classified into one method for providing the user with polarization glasses and another method where the user is not provided with polarization glasses.
A television according to the related art has been designed to display only a 2D image. In contrast, many developers and companies have recently conducted intensive research into a 3D imaging technology for use in digital broadcasting. However, detailed protocols related to a 3D broadcast signal processing technology have not been defined yet, so that broadcast content providers, broadcast stations, and DTV manufacturers have been thrown into a great confusion with regard to such 3D broadcast signal processing.